From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54E90C64EBD for ; Wed, 3 Oct 2018 00:35:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E699A206B2 for ; Wed, 3 Oct 2018 00:35:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E699A206B2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=davemloft.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726646AbeJCHVa (ORCPT ); Wed, 3 Oct 2018 03:21:30 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:52162 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726120AbeJCHVa (ORCPT ); Wed, 3 Oct 2018 03:21:30 -0400 Received: from localhost (c-67-183-145-105.hsd1.wa.comcast.net [67.183.145.105]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id E30B8142A355D; Tue, 2 Oct 2018 17:35:29 -0700 (PDT) Date: Tue, 02 Oct 2018 17:35:26 -0700 (PDT) Message-Id: <20181002.173526.155463905341442781.davem@davemloft.net> To: f.fainelli@gmail.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] net: systemport: Fix wake-up interrupt race during resume From: David Miller In-Reply-To: <20181002235204.26135-1-f.fainelli@gmail.com> References: <20181002235204.26135-1-f.fainelli@gmail.com> X-Mailer: Mew version 6.7 on Emacs 26 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 02 Oct 2018 17:35:30 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Florian Fainelli Date: Tue, 2 Oct 2018 16:52:03 -0700 > The AON_PM_L2 is normally used to trigger and identify the source of a > wake-up event. Since the RX_SYS clock is no longer turned off, we also > have an interrupt being sent to the SYSTEMPORT INTRL_2_0 controller, and > that interrupt remains active up until the magic packet detector is > disabled which happens much later during the driver resumption. > > The race happens if we have a CPU that is entering the SYSTEMPORT > INTRL2_0 handler during resume, and another CPU has managed to clear the > wake-up interrupt during bcm_sysport_resume_from_wol(). In that case, we > have the first CPU stuck in the interrupt handler with an interrupt > cause that has been cleared under its feet, and so we keep returning > IRQ_NONE and we never make any progress. > > This was not a problem before because we would always turn off the > RX_SYS clock during WoL, so the SYSTEMPORT INTRL2_0 would also be turned > off as well, thus not latching the interrupt. > > The fix is to make sure we do not enable either the MPD or > BRCM_TAG_MATCH interrupts since those are redundant with what the > AON_PM_L2 interrupt controller already processes and they would cause > such a race to occur. > > Fixes: bb9051a2b230 ("net: systemport: Add support for WAKE_FILTER") > Fixes: 83e82f4c706b ("net: systemport: add Wake-on-LAN support") > Signed-off-by: Florian Fainelli Applied, thanks Florian.